1997 â€“ Harvey E. Yates Company drills a test well in New Mexicoâ€™s Otero Mesa at the base of Alamo Mountain and discovers natural gas.

Oct. 1998 – After HEYCO hits gas on a second test well within the â€œBennett Ranch Unit,â€ the Bureau of Land Management (BLM) suspends all leases and new leasing, and begins an amendment to the governing 1986 White Sands Resource Management Plan (RMP) to reassess leasing in the Field Office. The RMP Amendment only addresses oil and gas leasing, with a full-scale revision delayed for a later time

Nov. 2000 â€“ A Draft RMP Amendment is issued. The Preferred Alternative would limit new surface disturbance in the grasslands to within 492 feet (150 meters) of existing roads to limit fragmentation.

April 2002 â€“ The Coalition for Otero Mesa is formed.

Jan. 2003 â€“ The Proposed RMP is issued and a new preferred alternative is identified and adopted to permit drilling activities with limits disturbance in the grassland to 5% of a leasehold at any given time. More lands are also opened to leasing â€“ 95% of the field office. Protests are filed by conservation groups and 3 State of New Mexico departments (Environment, Game & Fish, and Energy, Minerals & Natural Resources) and an extensive consistency review (challenging the planâ€™s inconsistencies with state programs) is filed by the Governor.

Aug. 2003 â€“ The New Mexico Wilderness Alliance submits its comprehensive Wilderness Inventory for the Greater Otero Mesa Area to the BLM, recommending 480,000 acres as eligible for wilderness designation.

Feb. 2004 â€“ Governor Bill Richardson issues an Executive Order directing all state agencies to seek and find ways to preserve and protect the resources of Otero Mesa from oil and gas drilling.

March 2004 â€“ The New Mexico Oil Conservation Commission begins to develop new rules to protect water and habitat on Otero Mesa. Rules are finalized â€“ prohibiting use of pits on Otero Mesa and requiring additional reporting and protection â€“ a few months later.

May 2004 â€“ BLM issues a Supplement to the RMP Amendment, providing additional closures for the endangered Aplomado falcon and adding in an acreage limitation of surface disturbance of 1,589 acres total, at which point BLM will consider the need for more NEPA.

January 2005 â€“ Record of Decision is issued, with no additional improvements.

April 2005 â€“ On Earth Day, a lawsuit challenging the RMP Amendment is filed by the Governor. This is the first time in history that the state of New Mexico sued the federal government over a public lands issue.

May 2005 â€“ A companion lawsuit challenging the RMP Amendment is filed by conservation groups, led by the New Mexico Wilderness Alliance.

June 2005 â€“ Notice issued to include a new lease on Otero Mesa, in the Bennett Ranch Unit, in the lease sale. Protests are filed, with the lease still ultimately sold to HEYCO (with the provision that it could only be formally issued once the protest is resolved) and the leasing decision is included in the pending lawsuits. The parties then enter into an agreement to stay issuance of the new lease and any more leasing on Otero Mesa until the lawsuits are resolved.

July 2005 â€“ Independent Petroleum Association of New Mexico intervenes in the case on the side of the BLM.

Sept. 2006 – The district court issues a ruling finding that the RMP Amendment was sufficient in terms of NEPA and compliance with other laws to approve decisions on which lands are available to lease. However, the court also finds that the decision to issue the lease was not valid, because the BLM still did not conduct the necessary analysis of impacts such as habitat fragmentation, prior to including the lease. The BLM was directed to go back and complete additional NEPA prior to issuing the lease.

Nov./Dec. 2006 â€“ The Governor and conservation groups appeal the parts of the district courtâ€™s decision upholding the RMP Amendment. The BLM initially appeals the part of the decision finding the lease invalid, but drops the appeal. In the interim, the Independent Petroleum Association maintains its appeal.

Sept. 2008 â€“ A hearing is held in front of the 10th Circuit Court of Appeals.

April 2009 â€“ The U.S. 10th Circuit Court of Appeals issues its decision on the litigation brought by the State of New Mexico, state agencies, and a number of conservation groups challenging the RMP Amendment for Otero and Sierra Counties. In addition to recognizing the ecological importance of Otero Mesa, the court specifically found that the RMP Amendment did not adequately consider potential impacts of oil and gas development in causing habitat fragmentation in the grasslands or in contaminating the Salt Basin Aquifer. Furthermore, the court found that BLMâ€™s entire RMP Amendment is flawed because the agency did not consider an alternative to protect all of Otero Mesa from oil and gas drilling. BLM will need to consider and analyze sufficient protections in a supplemental process.